art0hur0moh wrote:With a melting point of 700 deg C. Becomes highly explosive when in contact with water, causing the towers to vaporise during free fall.

I've seen cast iron explode because there was water on the surface of the sand mould before, it's a bit dramatic. I think that using raw aluminium as the core of a skyscraper would be a bad idea due to the elasticity of it, it would be an alloy or a composite with higher heat tolerances.

Aluminium. It would take the temperature up to the correct level to melt steel. Basically an incindery? Why no escape on the corners of the building? An H> between two poles holding safety line as people descend.